Normally, when I used to introduce locus my aim looked like this:Aim: How do we sketch the locus of points a fixed distance from a point?

This year it looked like this:Aim: How do cell phone towers determine the location of a customer?

Huge difference, and you can note the difference in the level of engagement the minute students read the aim walking into the room.

Before the break I found a really awesome lesson at Mathalicious.com. The lesson looked at locus, more specifically focused on the locus of points a fixed distance from a point. They really did a great job putting this lesson together. Below is a pic of a part of the lesson I did with my students.Essentially the lesson first seeks to answer: How many cell phone towers does it take to determine a customer's location?Students then go through a series of activities involving locus to determine this.

There are three main parts to the lesson but since I was using it to introduce locus, we just focused on that part of the lesson that looks at how many towers are needed to track a persons location. (Although we will probably later do the rest since the whole lesson is rich).I tried to make the lesson more personal to my students by using a map of Brooklyn instead of the provided map of Albuquerque. This was easy, just copied and pasted a map of Brooklyn to sketchpad and had students download the pre-arranged file off my website.

The lesson is a beauty, I really didn't have to change much. Overall, this really is a great lesson with very good questions. The lesson is also universally accessible, all of my students were engaged and I have the observation report to prove it!